The present invention relates to a medical heating electrode device and, more particularly, to a high-frequency capacitive heating electrode device which is applicable to the hyperthermia therapy for tumors and the like.
There is known a high-frequency hyperthermia therapy for treating a cancer by utilizing the fact that cancer cells are less resistant to heat than normal cells.
In a conventional high-frequency capacitive hyperthermia therapy, the area of a living body including a portion to be heated is situated between two plate electrodes and a high-frequency current is supplied between the electrodes from a high-frequency power source.
It is difficult, however, to effectively heat the target portion at the deep inside of a living body by such a conventional treatment, because the subcutaneous fat layer tends to be heated more intensively so that this treatment gives pain to the patient.
To overcome such a problem, a method has been proposed in which a high-frequency current is applied between a first electrode which has a device for circulating a cooling medium and can be applied to the vicinity of the lesional portion at the deep inside of a living body and a second electrode which has a larger electrode area than the first electrode so that only the vicinity of the first electrode may be heated and is applied to the surface of the living body.
For example, Japanese Utility Model Application Laid-Open (KOKAI) Nos. 63-3844 (1988) and 63-3845 (1988) (corresponding to European Patent Application Laid-Open No. 0251746 Al) discloses a high-frequency capacitive heating electrode device which is applicable to the surface of an endotract organ.
The electrode device disclosed in Japanese Utility Model Application Laid-Open (KOKAI) No. 63-3845 (1988) is a high-frequency heating electrode device which comprises a thick-walled container of a flexible polymer which is equipped with passages for respectively introducing and discharging a cooling medium, an electrode easy to transform and disposed on the inner surface opposite to the open surface of the thick-walled container, and a flexible polymer film for sealing the open surface of the thick-walled container. This electrode device transforms in conformity with the configuration of the surface of the body (the outer surface of a living body and the surface of an endotract organ) and allows the desired portion in the vicinity of the electrode device to be selectively and reliably heated. Since the electrode does not come into close contact with the surface of the body, the electrode device is safe.
The electrode device disclosed in Japanese Utility Model Application Laid-Open (KOKAI) No. 63-3844 (1988) is a heating electrode device which comprises the high-frequency heating electrode device disclosed in Japanese Patent Application Laid-Open (KOKAI) No. 63-3845 (1988) and a gastight bag-like member disposed on the back surface of the thick-walled container of the high-frequency heating electrode device and having a function of introducing and discharging a gas, so that the electrode device is secured to the target lesional portion on the inner surface of an endotract organ (e.g., the inner surface of the vagina) without the necessity for separately preparing an electrode fixing device.
A high-frequency capacitive heating electrode device according to the present invention has been so devised as to be applicable to the treatment for a cancer of the uterine cervix, which is the surface of the endotract organ, and for the cancer which has infiltrated into the peripheral portion of the uterine cervix.